#197 "ignoring null tag" warning

[René Stadler]

Running ctags 5.7 (from Ubuntu Gutsy beta) on a Python file that contains something like this:

def x ():
a=_class
""

Leads to this warning being printed:

ctags: Warning: ignoring null tag in test-ctags.py

The example code looks very artificial, but is in fact valid Python code. The important parts are the string "class" at the end of line 2 and the second " character at the end of line 3. You can put anything before "class" and " in line 2 and 3, it will always trigger the warning as long as the strings appear shifted by 2 columns. You can also replace "class" with "def".

This works fine with ctags 5.6 from Ubuntu Feisty.

My real code portion that triggers the warning is this part of a class method:

>>>>>>>>

def detach (self):

model = self.view.props.model
sort_id, sort_order = tree_sortable_get_sort_column_id (model)
if sort_id >= 0:
self.app.state.sort_column = self.find_item_class (id = sort_id)
if sort_order == gtk.SORT_ASCENDING:
self.app.state.sort_order = "ascending"
else:
self.app.state.sort_order = "descending"

>>>>>>>>>>

Here, the expression "self.find_item_class" has the triggering "class" string. The " match is the closing quote of the "ascending" string two lines below that.

Strange, isn't it?

[Elliott Hughes]

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(assigning to elias, ctags' Python maintainer.)

[Elias Pschernig]

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I cannot reproduce this with SVN trunk (revision 628). Did you use any options to ctags? I tried both examples, and here I get a single function "x" and "detach", respectively. Without any warnings.

[René Stadler]

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Tried SVN trunk now, same thing. You don't even need a method, just write

x=_class
""

at toplevel.

[Elias Pschernig]

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For some reason, passing --enable-maintainermode to configure made the warning not appear. Building normally, I could reproduce and committed a fix to svn (revision 629). Since you already tried the SVN version, maybe you can confirm that it fixes the problem.

[René Stadler]

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Confirming, SVN trunk works now.

[Elliott Hughes]

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(closing because the submitter has confirmed the fix, a test case has been added, and the NEWS file has been updated.)